More precisely, the present invention relates to a monitoring system, comprising a sleep sensing unit and a base unit. The sleep sensing unit is provided with sensor(s) (generally sensing functions), for example ballistography-based sensing functions. The base unit is coupled to the sleep sensing unit, and is configured to receive data measured by the sleep sensing unit and its own sensors. The base unit may inform the user of his/her sleep patterns, e.g. how often the user is awake during the night, or how many times the user enters the REM phase, and generally provide sleep stages and cycles timings like the one provided by PolySomnoGraphy systems.
Such systems as known in the art base the observations on the knowledge of what happens when the user is in a specific sleep stage. Generally, the average adult's sleep goes through sleep phases of REM sleep (paradoxical sleep) and NREM sleep; in average, there are 3-5 NREM/REM cycles, with average duration of 90-100 minutes. The NREM sleep is further divided into a light sleep and a deep sleep; in average, the deep sleep phases tend to be longer in 1st part of the night, while the REM sleep tends to be longer in the 2nd part of the night. For example in the light sleep, the user's breath is usually slower than when awake, and the heart rate is slowed down; in deep sleep, the heart rate and breathing frequency is further slowed, the muscles are relaxed and the movements are very little or non-existent; in REM phase, the heart rate and breathing frequency may increase again, and their variability is increased.
Some of the devices known in the art are configured to assist the user by providing other functionalities, such as a snooze alarm; some of the bedside devices may dim the lights when the user falls asleep, and put on the lights again once the user is awakened, or is to be awakened; some of the units serve mostly medical purposes, monitor the user's health, and are capable of issuing warning when the user's condition worsens.
Similar devices are known in the art. For example, GB2447640 describes a sensor wirelessly coupled to a base station. The sensor is head-worn and captures EEG of the user, while the base station processes the data and is capable of adjusting the user's sleep state. Another example is given in WO2007052108, which describes a system of sensors able to monitor medical conditions such as asthma, sleep apnea or labor, and notify medical personnel if needed. However, the system disclosed in WO200752108 does not provide the user with any means to adjust his/her sleep state.
Generally, the prior art systems are either too simple, thus not providing all the necessary information and not having all the required functionalities, or too complicated, thus being difficult to operate, prone to errors and failures, and providing the user with outputs that are confusing for him/her.
Therefore, there is a need to propose a user-friendly simple-to-use though elaborate sleep assist system.